The Coordinate-Wise Core for Multiple-Type Housing Markets is Second-Best Incentive Compatible

Abstract

We consider the generalization of Shapley and Scarf''s (1974) model of trading indivisible objects (houses) to so-called multiple-type housing markets. We show (Theorem 1) that the prominent solution for these markets, the coordinate-wise core rule, is second-best incentive compatible. In other words, there exists no other strategy-proof trading rule that Pareto dominates the coordinate-wise core rule. Given that for multiple-type housing markets Pareto efficiency, strategy-proofness, and individual rationality are not compatible, by Theorem 1 we show that applying the coordinate-wise core rule is a minimal concession with respect to Pareto efficiency while preserving strategy-proofness and individual rationality.microeconomics ;